Narrow States Research Articles

Search for new resonant states in10C and11C and their impact on the cosmological lithium problem

The observed primordial 7Li abundance in metal-poor halo stars is found to be lower than its Big-Bang nucleosynthesis (BBN) calculated value by a factor of approximately three. Some recent works suggested the possibility that this discrepancy originates from missing resonant reactions which would destroy the 7Be, parent of 7Li. The most promising candidate resonances which were found include a possibly missed 1- or 2- narrow state around 15 MeV in the compound nucleus 10C formed by 7Be+3He and a state close to 7.8 MeV in the compound nucleus 11C formed by 7Be+4He. In this work, we studied the high excitation energy region of 10C and the low excitation energy region in 11C via the reactions 10B(3He,t)10C and 11B(3He,t)11C, respectively, at the incident energy of 35 MeV. Our results for 10C do not support 7Be+3He as a possible solution for the 7Li problem. Concerning 11C results, the data show no new resonances in the excitation energy region of interest and this excludes 7Be+4He reaction channel as an explanation for the 7Li deficit.

Fluorescent Cross-Linked Polystyrene Perylenebisimide/Oligo(p-Phenylenevinylene) Microbeads with Controlled Particle Size, Tunable Colors, and High Solid State Emission

A series fo cross-linked fluorescent polystyrene (PS) microbeads with narrow size distribution and intense solid state emission was developed. Fluorophores based on perylene bisimide (PBI) and oligo(p-phenylenevinylene) (OPV) designed as acrylic cross-linkers were introduced into the polymerization recipe in a two-stage dispersion polymerization, carried out in ethanol in the presence of poly(vinylpyrrolidone) (PVP) as stabilizer. The structural design permitted introduction of up to 10(-5) moles of the fluorophores into the polymerization medium without fouling of the dispersion. The particle size measured using dynamic light scattering (DLS) indicated that they were nearly monodisperse with size in the range 2-3 μm depending on the amount of fluorophore incorporated. Fluorescence microscope images of ethanol dispersion of the sample exhibited intense orange red emission for PS-PBI-X series and green emission for PS-OPV-X series. A PS incorporated with both OPVX and PBIX exhibited dual emission upon exciting at the OPV wavelength of 350 nm and PBI wavelength of 490 nm, respectively. The low incorporation of fluorophore resulted in almost complete absence of aggregation induced reduction in fluorescence as well as red-shifted aggregate emission. The solid state emission quantum yield measured using integrating-sphere setup indicated a very high quantum yield of ϕpowder = 0.71 for PS-OPV-X and ϕpowder = 0.25 for PS-PBI-X series. The cross-linked PS microbeads incorporating both OPV and PBI chromophores had a ϕpowder = 0.33 for PBI emission and ϕpowder = 0.20 for OPV emission. This strategy of introducing fluorophore as cross-linkers into the PS backbone is very versatile and amenable to simultaneous addition of different suitably designed fluorophores emitting at different wavelengths.

Perceptual narrowing in the context of increased variation: Insights from bilingual infants

Human infants become native-language listeners through a process of perceptual narrowing. Monolingual infants are initially sensitive to a wide range of language-relevant contrasts. However, as they mature and gain native-language experience, their sensitivity to nonnative contrasts declines. Here, we consider the case of infants growing up bilingual as a window into how increased variation affects early perceptual development. These infants encounter different meaningful contrasts in each of their languages, and must also attend to contrasts that occur between their languages. Bilingual infants share many classic developmental patterns with monolinguals. However, they also show unique developmental patterns in the perception of native distinctions such as U-shaped trajectories and dose-response relationships, and show some enhanced sensitivity to nonnative distinctions. Analogous developmental patterns can be observed in individuals exposed to two nonlinguistic systems in domains such as music and face perception. Some preliminary evidence suggests that bilingual individuals might retain more sensitivity to nonnative contrasts, reaching a less narrow end state than monolinguals. Nevertheless, bilingual infants do become perceptually specialized native listeners to both of their languages, despite increased variation and differing patterns of perceptual development in comparison to monolinguals.

Restricting State Part C Eligibility Policy is Associated with Lower Early Intervention Utilization

To examine if state differences in early intervention (EI) utilization can be explained by recent restrictions on EI state eligibility policy. The sample (n = 923), derived from the 2009/10 National Survey of Children with Special Health Care Needs, included CSHCN who were ages 0-3 with a developmental delay or disability that affected their function. Multi-level logistic modeling was used to describe state differences in EI utilization and to determine if narrower state eligibility policy explained these differences. EI utilization ranged from 6 to 87 % across states. Having a severe condition (β = 0.99, SE = 0.28) and a usual source of care (β = 0.01, SE = 0.001) was associated with higher odds of utilizing EI. Compared to a diagnosed disability, having a developmental delay (β = -0.61, SE = 0.20) was associated with lower odds of utilizing EI. Living in a state with narrow and narrower state eligibility policy (β = -0.18, SE = 0.06) was significantly associated with lower odds of EI utilization, and this effect was strongest for children with the most severe functional impairments. Significant state variation in EI rates exists that can be explained, in part, by the restrictiveness of state eligibility criteria. Children with the most severe functional impairments appear to be least likely to utilize EI in states with the most restrictive eligibility policies.

Heavy Flavor Results from DØ

Presented are summaries of four heavy flavour analyses by the DØ Collaboration between August 2011 and June 2012. Using up to 10.4 fb−1 of pp¯ collisions at s=1.96 TeV accumulated by the DØ detector at the Fermilab Tevatron collider, we find evidence for the two-body decay Bs0→J/ψf2′(1525) and measure the branching fraction of these decays relative to Bs0→J/ψϕ as Rf2′/ψ=0.22±0.05(stat.)±0.04(syst). The Λb0 lifetime is measured using the fully reconstructed decay Λb0→J/ψΛ0, along with the lifetime of the topologically similar decay channel Bd0→J/ψKs0. The analyses yields results of τ(Λb0)=1.303±0.075(stat.)±0.035(syst.) ps, τ(Bd0)=1.508±0.025(stat.)±0.043(syst.) ps, and τ(Λb0)/τ(Bd0)=0.864±0.052(stat.)±0.033(syst.) ps. A narrow mass state is observed that decays into ϒ(1S)+γ with an invariant mass of 10.551±0.014(stat.)±0.017(syst.) GeV/c2. Finally, the semileptonic charge asymmetry is measured to be asls=[−1.08±0.72(stat.)±0.17(syst.)]% using the decay channel Bs0(B¯s0)→Ds∓μ±X.

Emotional Maltreatment Reports in Children: The Influence of State Statutes and Co-occurring Maltreatment

Allegations of emotional maltreatment pose a challenge for child welfare systems, partially because state statutes tend to use vague definitions. In this study, the relationship between statutory definitions and reported rates of emotional maltreatment was examined. Using data from the National Child Abuse and Neglect Data System (NCANDS), comparisons were made of the rates of emotional maltreatment in broad versus narrow state statutes. Results indicated that states with broad statutes had higher rates of both alleged and substantiated emotional maltreatment, although only in cases where emotional maltreatment was the sole type of reported abuse. The results buttress the argument that definitions of emotional maltreatment suffer from a lack of clarity and consistency across the United States.

Quantification of deep hole-trap filling by molecular p-doping: Dependence on the host material purity

The p-doping effect of the fluorinated fullerene C60 F36 doped into organic thin films of N,N,N′,N′-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD) of different purification grades is systematically investigated by photoemission spectroscopy. By reducing the molar doping ratio to MR=2.9×10−4, the Fermi-level shift upon doping is resolved in particular at very low doping concentrations. In comparison to four times sublimated MeO-TPD, 5 times more C60F36 molecules have to be doped into unpurified MeO-TPD films to shift the Fermi-level just above its intrinsic position. This finding is discussed in terms of a statistical model, showing that narrow deep hole-trap states are additionally present in the unpurified host material which are hindering an efficient generation of free charge carriers at molar doping ratios below MR=0.002.

Same-Sex Marriages in Bankruptcy: A Path Out of the Public Policy Quagmire

Up to this point the bankruptcy courts have had little difficulty balancing the interstitial nature of bankruptcy in the context of heterosexual unions. When it comes to the recognition of marriage and its attendant rights and obligations, bankruptcy courts have relied on the Supreme Court’s command in Butner v. United States and looked to state law to determine both the legality of the marriage as well as the existence of rights that arise as a result of the union. Rarely have the bankruptcy courts been asked or required to examine conflicting state domestic relations laws when ruling on the validity of a marriage. Can a bankruptcy court treat as a valid a marriage that the forum state’s law declares invalid? Can the court recognize the incidences of marriage if the forum state law either implicitly or explicitly prohibits such recognition? Is the court required to follow the public policy of the forum state or is the court free to ignore it? This article attempts to answer these questions by examining DOMA § 2 and the myriad state laws regarding same-sex relationships, The article places the marriage prohibition statutes in an historical context, describing the narrow construction state courts have traditionally given such statutes even during the miscegenation era. To the extent a conflict cannot be avoided, the article promotes a federal choice of law rule that focuses on underlying bankruptcy policies rather than state public policies regarding same-sex relationships.

Ξbaryon strong decays in a chiral quark model

The strong decays of $\Xi$ baryons up to N=2 shell were studied in a chiral quark model. The strong decay properties of these well-established ground decuplet baryons were reasonably described. We found that (i) $\Xi(1690)$ and $\Xi(1820)$ could be assigned to the spin-parity $J^P=1/2^-$ state $|70,^{2}{8},1,1,1/2^->$ and the spin-parity $J^P=3/2^-$ state $|70,^{2}{8},1,1,3/2^->$, respectively. Slight configuration mixing might exist in these two negative parity states. (ii) $\Xi(1950)$ might correspond to several different $\Xi$ resonances. The broad states ($\Gamma\sim 100$ MeV) observed in the $\Xi\pi$ channel could be classified as the pure $J^P=5/2^-$ octet state $\Xi^0|70,^{4}8,1,1,5/2^->$ or the mixed state $|\Xi 1/2^->_3 $ with $J^P=1/2^-$. The $\Xi$ resonances with moderate width ($\Gamma\sim 60$ MeV) observed in the $\Xi\pi$ channel might correspond to the $J^P=1/2^+$ excitation $|56,^{4}10,2,2,1/2^+>$. The second orbital excitation $|56,^{4}10,2,2,3/2^+>$ and the mixed state $|\Xi 1/2^->_1$ might be candidates for the narrow width state observed in the $\Lambda \bar{K}$ channel, however, their spin-parity numbers are incompatible with the moment analysis of the data. (iii) $\Xi(2030)$ could not be assigned to either any spin-parity $J^P=7/2^+$ states or any pure $J^P=5/2^+$ configurations. It seems to favor the $|70,^{2}8,2,2,3/2^+>$ assignment, however, its spin conflicts with the moment analysis of the data. To find more $\Xi$ resonances, the observations in the $\Xi(1530)\pi$ and $\Sigma(1385) \bar{K}$ channels are necessary.

Light-Wave Mixing and Scattering with Quantum Gases

We present a semiclassical theoretical framework on light-wave mixing and scattering with single-component quantum gases. We show that these optical processes originating from elementary excitations with dominant collective atomic recoil motion are stimulated Raman or hyper-Raman in nature. In the forward direction the wave-mixing process, which is the most efficient process in normal gases, is strongly reduced by the condensate structure factor even though the Bogoliubov dispersion relation automatically compensates the optical-wave phase mismatch. In the backward direction, however, the free-particle-like condensate structure factor and Bogoliubov dispersion result in highly efficient light-wave mixing and collective atomic recoil motion that are enhanced by a stimulated hyper-Raman gain and a very narrow two-photon motional state resonance.

Search for resonant top-antitop production in the lepton plus jets decay mode using the full CDF data set.

This Letter reports a search for a narrow resonant state decaying into two W bosons and two b quarks where one W boson decays leptonically and the other decays into a quark-antiquark pair. The search is particularly sensitive to top-antitop resonant production. We use the full data sample of proton-antiproton collisions at a center-of-mass energy of 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, corresponding to an integrated luminosity of 9.45 fb(-1). No evidence for resonant production is found, and upper limits on the production cross section times branching ratio for a narrow resonant state are extracted. Within a specific benchmark model, we exclude a Z' boson with mass, M(Z'), below 915 GeV/c(2) decaying into a top-antitop pair at the 95% credibility level assuming a Z' boson decay width of Γ(Z') = 0.012 M(Z'). This is the most sensitive search for a narrow qq-initiated tt resonance in the mass region below 750 GeV/c(2).

A narrow quasi-bound state of the DNN system

Abstract We have investigated a charmed system of DNN (composed of two nucleons and a D meson) by a complementary study with a variational calculation and a Faddeev calculation with fixed-center approximation (Faddeev-FCA). In the present study, we employ a DN potential based on a vector–meson exchange picture in which a resonant Λ c ( 2595 ) is dynamically generated as a DN quasi-bound state, similarly to the Λ ( 1405 ) as a K ¯ N one in the strange sector. As a result of the study of variational calculation with an effective DN potential and three kinds of NN potentials, the D N N ( J π = 0 − , I = 1 / 2 ) is found to be a narrow quasi-bound state below Λ c ( 2595 ) N threshold: total binding energy ∼ 225 MeV and mesonic decay width ∼ 25 MeV . On the other hand, the J π = 1 − state is considered to be a scattering state of Λ c ( 2595 ) and a nucleon. These results are essentially supported by the Faddeev-FCA calculation. By the analysis of the variational wave function, we have found a unique structure in the D N N ( J π = 0 − , I = 1 / 2 ) such that the D meson stays around the center of the total system due to the heaviness of the D meson.

Lüscher’s finite size method with twisted boundary conditions: An application to theJ/ψ−ϕsystem to search for a narrow resonance

We investigate an application of twisted boundary conditions for study of low-energy hadron-hadron interactions with L\"ushcer's finite size method. It allows us to calculate the phase shifts for elastic scattering of two hadrons at any small value of the scattering momentum even in a finite volume. We then can extract model independent information of low-energy scattering parameters such as the scattering length, the effective range and the effective volume from the $S$-wave and $P$-wave scattering phase shifts through the effective range expansion. This approach also enables us to examine the existence of near-threshold and narrow resonance states, of which characteristic is observed in many of newly discovered charmonium-like $XYZ$ mesons. As a simple example, we demonstrate our method for low-energy $J/\psi$-$\phi$ scatterings to search for Y(4140) resonance using 2+1 flavor PACS-CS gauge configurations at the lightest pion mass, $m_{\pi}=156$ MeV.

η-meson production in the resonance-energy region

We perform an updated coupled-channel analysis of eta-meson production including all recent photoproduction data on the proton. The dip observed in the differential cross sections at c.m. energies W=1.68 GeV is explained by destructive interference between the $S_{11}(1535)$ and $S_{11}(1560)$ states. The effect from $P_{11}(1710)$ is found to be small but still important to reproduce the correct shape of the differential cross section. For the $\pi^- N \to \eta N$ scattering we suggest a reaction mechanism in terms of the $S_{11}(1535)$, $S_{11}(1560)$, and $P_{11}(1710)$ states. Our conclusion on the importance of the $S_{11}(1535)$, $S_{11}(1560)$, and $P_{11}(1710)$ resonances in the eta-production reactions is in line with our previous results. No strong indication for a narrow state with a width of 15 MeV and the mass of 1680 MeV is found in the analysis. $\eta N$ scattering length is extracted and discussed.

THE MARGIN OF APPRECIATION IN A, B AND C V IRELAND: A DISPROPORTIONATE RESPONSE TO THE VIOLATION OF WOMEN’S REPRODUCTIVE FREEDOM

In the case of A, B & C v Ireland the European Court of Human Rights found that there had been an interference with the applicants’ right to private life. However, “owing to the acute sensitivity of the moral and ethical issues raised by abortion” Ireland was afforded a wide margin of appreciation and was not found to have breached the Convention. This paper argues that the Court’s application of the margin of appreciation doctrine was disproportionate. Firstly, the existence of ‘consensus’ throughout Europe on permitting abortions where a woman’s health and wellbeing are at risk should have contracted the power of discretion afforded to national authorities. Secondly, the blanket deference is problematic as a matter of equality. The sensitivity of the abortion question is not a sufficient justification for judicial restraint. In light of the discriminatory nature of the policies in dispute, as well as the presence of an established principle that operates to narrow state discretion (consensus), European supervision should not have been restrained. Rather, it should have been heightened.

Narrow Bound States of the DNN System

We report on a recent calculation of the properties of the $DNN$ system, a charmed meson with two nucleons. The system is analogous to the $\bar K NN$ system substituting a strange quark by a charm quark. Two different methods are used to evaluate the binding and width, the Fixed Center approximation to the Faddeev equations and a variational calculation. In both methods we find that the system is bound by about 200 MeV and the width is smaller than 40 MeV, a situation opposite to the one of the $\bar K NN$ system and which makes this state well suited for experimental observation.

Pulse pile-up recovery for the front-end electronics of the PANDA Electromagnetic Calorimeter

At the future Facility for Antiproton and Ion Research near Darmstadt in Germany the PANDA detector will be employed to study the charmonium spectrum and to search for narrow exotic hadronic states, predicted by Quantum Chromodynamics. In the PANDA experiment, 1.5 to 15 GeV/c anti-protons will annihilate with a hydrogen target at an average rate of 20MHz. Among the sub-detectors of PANDA is the Electromagnetic Calorimeter (EMC) planned for the studies of electromagnetic transitions and neutral meson decays. Due to the high annihilation rates, the EMC will be exposed to single-detector hit rates up to 500kHz, which may lead to pulse overlap. Hence, to recover the energy and time information of the overlapping pulses, a pulse pile-up recovery method is developed. The method is easy to implement in FPGA for online data processing. The Constant Fraction Timing algorithm is applied at the trailing edge to determine the time stamp of pile-up pulses. The energy and the time information of pile-up pulses can be recovered up to time differences of 50ns, equal to the pulse rise-time, in a large dynamic energy range.

Observation of ExcitedΛb0Baryons

Using pp collision data corresponding to 1.0 fb−1 integrated luminosity collected by the LHCb detector, two narrow states are observed in the Λb0π+π− spectrum with masses 5911.97±0.12(stat)±0.02(syst)±0.66(Λb0 mass) MeV/c2 and 5919.77±0.08(stat)±0.02(syst)±0.66(Λb0 mass) MeV/c2. The significances of the observations are 5.2 and 10.2 standard deviations, respectively. These states are interpreted as the orbitally excited Λb0 baryons, Λb*0(5912) and Λb*0(5920).Received 16 May 2012DOI:https://doi.org/10.1103/PhysRevLett.109.172003This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.© 2012 CERN, for the LHCb Collaboration

Study of the narrow structure at 1685 MeV in [formula omitted

Results of a coupled channel isobar analysis of new high-statistics data on γp→pη from MAMI are presented. A fit using known broad resonances and only standard background amplitudes cannot describe the relatively narrow peaking structure in the cross section in the mass region of 1660–1750 MeV which follows a minimum. An improved description of the data can be reached by either assuming the existence of a narrow resonance at a mass of about 1700 MeV with small photo-coupling or by a threshold effect. In the latter case the observed structure is explained by a strong (resonant or non-resonant) γp→ωp coupling in the S11 partial wave. When the beam asymmetry data, published by part of the GRAAL Collaboration, are included in the fit, the solution with a narrow P11 state is slightly preferred. In that fit, mass and width of the hypothetical resonance are determined to M∼1694 MeV and Γ∼40 MeV, respectively, and the photo-coupling to BrηNA1/2p∼2.6⋅10−3 GeV−1/2. High-precision measurements of the target asymmetry and F-observable are mandatory to establish the possible existence of such a narrow state and to provide the necessary information to define which partial wave is responsible for the structure observed in the data.

Core excitations and narrow states beyond the proton dripline: The exotic nucleus21Al

We present the first predictions for the widths of resonance states in a so-far unobserved exotic isotope beyond the proton dripline, ${}^{21}$Al. For this purpose we employ mirror symmetry between the widths of low-lying resonance states and the asymptotic normalization coefficients (ANC) of their mirror analogs. The latter are extracted from a recently measured peripheral reaction ${}^{20}$O($d$,$p$)${}^{21}$O while the positions of resonances are estimated within a microscopic cluster model and a two-body potential model. We have found that ${}^{21}$Al should have two low-lying states decaying into the ${}^{20}$Mg+$p$ channel and three states at higher energy, built on the 2${}^{+}$ core excited state and decaying into the ${}^{20}$Mg(2${}^{+})+p$ channel. The widths of all these states are much smaller than their energies, which makes experimental spectroscopic studies of this isotope beyond the proton dripline possible.